SEOUL, SOUTH KOREA – North Korea threatened Tuesday to change the rules that, it said, gave “special privileges” for the 100 South Korean companies producing light industrial products at the Kaesong Industrial Complex inside North Korea 40 miles north of here.

North Korea raised the future of the complex in a 22-minute session to which it summoned a South Korean delegation that attended in hopes of gaining access to a South Korean worker. The South Korean team returned here without seeing the worker, who was jailed on March 30 for making critical remarks about the North Korean regime to a waitress in a snack bar.

South Korea’s Unification Ministry, announcing results of the meeting, said the North Koreans wanted to increase the amount of money the South Koreans pay for the 40,000 workers hired by the South Korean factories. South Korean factories give $55 a month for each worker to a North Korean agency, which pays the workers in chits for food, clothing, and other necessities.

Lee Chung-joo, a spokesperson for the ministry, said the South Koreans placed “top priority” on freedom for the jailed worker, an engineer for Hyundai Asan, which built the complex.

The formal exchange appeared to have been chilly. The South Korean delegation called on North Korea to “cooperate” in developing the complex, the only point of current North-South cooperation after a year of rising rhetoric from the North.

North and South Korean officials spent most of the day haggling over whether to meet in a North Korean administrative office or in the more neutral complex headquarters. South Korean officials yielded after eight informal rounds of talks lasting nearly 12 hours.

Hopes were high before the meeting in view of the downward spiral in North-South relations since North Korea test-fired a long-range missile on April 5. North Korea has said it will resume making nuclear warheads and would regard South Korea’s joining the US-inspired Proliferation Security Initiative for monitoring and interdicting traffic in nuclear components and missiles as “an act of war.”

It was the first time officials have held a formal talk at Kaesong since shortly before the inauguration in February of last year of South Korea’s President Lee Myung Bak, excoriated by the North as a “traitor” and “lackey” for the Americans.